I'm absolutely not an expert in this field, but here's what I was thinking (sorry, if it doesn't make sense): What if it was possible to distribute SDK and the framework as two separate packages? That would spare the trouble of OSMF and TLF inclusion for the base (SDK) package? Additionally, there's Tamarin that can produce playerglobal.swc (of course, it's not what you want, but read on), I think it shouldn't be a technical problem to create "interfaces" i.e. classes mirroring the actual Flash Player classes with methods marked as "native" and compile an SWC from it using Tamarin - that would require some reverse engineering + quite a bit of a handwork, but from the first glance may be possible... Worst case, the binary package may come with the "fake" sources that technically reflect the classes built into Flash player. I think this is how Flash Develop used to be distributed some time ago - they had all the AS3 classes written themselves, the interfaces, that is.
Or does this sound hectic? :) Best. Oleg